xref: /openbmc/linux/include/net/sock.h (revision 8781e5df)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Definitions for the AF_INET socket handler.
8  *
9  * Version:	@(#)sock.h	1.0.4	05/13/93
10  *
11  * Authors:	Ross Biro
12  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13  *		Corey Minyard <wf-rch!minyard@relay.EU.net>
14  *		Florian La Roche <flla@stud.uni-sb.de>
15  *
16  * Fixes:
17  *		Alan Cox	:	Volatiles in skbuff pointers. See
18  *					skbuff comments. May be overdone,
19  *					better to prove they can be removed
20  *					than the reverse.
21  *		Alan Cox	:	Added a zapped field for tcp to note
22  *					a socket is reset and must stay shut up
23  *		Alan Cox	:	New fields for options
24  *	Pauline Middelink	:	identd support
25  *		Alan Cox	:	Eliminate low level recv/recvfrom
26  *		David S. Miller	:	New socket lookup architecture.
27  *              Steve Whitehouse:       Default routines for sock_ops
28  *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
29  *              			protinfo be just a void pointer, as the
30  *              			protocol specific parts were moved to
31  *              			respective headers and ipv4/v6, etc now
32  *              			use private slabcaches for its socks
33  *              Pedro Hortas	:	New flags field for socket options
34  */
35 #ifndef _SOCK_H
36 #define _SOCK_H
37 
38 #include <linux/hardirq.h>
39 #include <linux/kernel.h>
40 #include <linux/list.h>
41 #include <linux/list_nulls.h>
42 #include <linux/timer.h>
43 #include <linux/cache.h>
44 #include <linux/bitops.h>
45 #include <linux/lockdep.h>
46 #include <linux/netdevice.h>
47 #include <linux/skbuff.h>	/* struct sk_buff */
48 #include <linux/mm.h>
49 #include <linux/security.h>
50 #include <linux/slab.h>
51 #include <linux/uaccess.h>
52 #include <linux/page_counter.h>
53 #include <linux/memcontrol.h>
54 #include <linux/static_key.h>
55 #include <linux/sched.h>
56 #include <linux/wait.h>
57 #include <linux/cgroup-defs.h>
58 #include <linux/rbtree.h>
59 #include <linux/filter.h>
60 #include <linux/rculist_nulls.h>
61 #include <linux/poll.h>
62 
63 #include <linux/atomic.h>
64 #include <linux/refcount.h>
65 #include <net/dst.h>
66 #include <net/checksum.h>
67 #include <net/tcp_states.h>
68 #include <linux/net_tstamp.h>
69 #include <net/smc.h>
70 #include <net/l3mdev.h>
71 
72 /*
73  * This structure really needs to be cleaned up.
74  * Most of it is for TCP, and not used by any of
75  * the other protocols.
76  */
77 
78 /* Define this to get the SOCK_DBG debugging facility. */
79 #define SOCK_DEBUGGING
80 #ifdef SOCK_DEBUGGING
81 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
82 					printk(KERN_DEBUG msg); } while (0)
83 #else
84 /* Validate arguments and do nothing */
85 static inline __printf(2, 3)
86 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
87 {
88 }
89 #endif
90 
91 /* This is the per-socket lock.  The spinlock provides a synchronization
92  * between user contexts and software interrupt processing, whereas the
93  * mini-semaphore synchronizes multiple users amongst themselves.
94  */
95 typedef struct {
96 	spinlock_t		slock;
97 	int			owned;
98 	wait_queue_head_t	wq;
99 	/*
100 	 * We express the mutex-alike socket_lock semantics
101 	 * to the lock validator by explicitly managing
102 	 * the slock as a lock variant (in addition to
103 	 * the slock itself):
104 	 */
105 #ifdef CONFIG_DEBUG_LOCK_ALLOC
106 	struct lockdep_map dep_map;
107 #endif
108 } socket_lock_t;
109 
110 struct sock;
111 struct proto;
112 struct net;
113 
114 typedef __u32 __bitwise __portpair;
115 typedef __u64 __bitwise __addrpair;
116 
117 /**
118  *	struct sock_common - minimal network layer representation of sockets
119  *	@skc_daddr: Foreign IPv4 addr
120  *	@skc_rcv_saddr: Bound local IPv4 addr
121  *	@skc_hash: hash value used with various protocol lookup tables
122  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
123  *	@skc_dport: placeholder for inet_dport/tw_dport
124  *	@skc_num: placeholder for inet_num/tw_num
125  *	@skc_family: network address family
126  *	@skc_state: Connection state
127  *	@skc_reuse: %SO_REUSEADDR setting
128  *	@skc_reuseport: %SO_REUSEPORT setting
129  *	@skc_bound_dev_if: bound device index if != 0
130  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
131  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
132  *	@skc_prot: protocol handlers inside a network family
133  *	@skc_net: reference to the network namespace of this socket
134  *	@skc_node: main hash linkage for various protocol lookup tables
135  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
136  *	@skc_tx_queue_mapping: tx queue number for this connection
137  *	@skc_rx_queue_mapping: rx queue number for this connection
138  *	@skc_flags: place holder for sk_flags
139  *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
140  *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
141  *	@skc_incoming_cpu: record/match cpu processing incoming packets
142  *	@skc_refcnt: reference count
143  *
144  *	This is the minimal network layer representation of sockets, the header
145  *	for struct sock and struct inet_timewait_sock.
146  */
147 struct sock_common {
148 	/* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
149 	 * address on 64bit arches : cf INET_MATCH()
150 	 */
151 	union {
152 		__addrpair	skc_addrpair;
153 		struct {
154 			__be32	skc_daddr;
155 			__be32	skc_rcv_saddr;
156 		};
157 	};
158 	union  {
159 		unsigned int	skc_hash;
160 		__u16		skc_u16hashes[2];
161 	};
162 	/* skc_dport && skc_num must be grouped as well */
163 	union {
164 		__portpair	skc_portpair;
165 		struct {
166 			__be16	skc_dport;
167 			__u16	skc_num;
168 		};
169 	};
170 
171 	unsigned short		skc_family;
172 	volatile unsigned char	skc_state;
173 	unsigned char		skc_reuse:4;
174 	unsigned char		skc_reuseport:1;
175 	unsigned char		skc_ipv6only:1;
176 	unsigned char		skc_net_refcnt:1;
177 	int			skc_bound_dev_if;
178 	union {
179 		struct hlist_node	skc_bind_node;
180 		struct hlist_node	skc_portaddr_node;
181 	};
182 	struct proto		*skc_prot;
183 	possible_net_t		skc_net;
184 
185 #if IS_ENABLED(CONFIG_IPV6)
186 	struct in6_addr		skc_v6_daddr;
187 	struct in6_addr		skc_v6_rcv_saddr;
188 #endif
189 
190 	atomic64_t		skc_cookie;
191 
192 	/* following fields are padding to force
193 	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
194 	 * assuming IPV6 is enabled. We use this padding differently
195 	 * for different kind of 'sockets'
196 	 */
197 	union {
198 		unsigned long	skc_flags;
199 		struct sock	*skc_listener; /* request_sock */
200 		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
201 	};
202 	/*
203 	 * fields between dontcopy_begin/dontcopy_end
204 	 * are not copied in sock_copy()
205 	 */
206 	/* private: */
207 	int			skc_dontcopy_begin[0];
208 	/* public: */
209 	union {
210 		struct hlist_node	skc_node;
211 		struct hlist_nulls_node skc_nulls_node;
212 	};
213 	unsigned short		skc_tx_queue_mapping;
214 #ifdef CONFIG_XPS
215 	unsigned short		skc_rx_queue_mapping;
216 #endif
217 	union {
218 		int		skc_incoming_cpu;
219 		u32		skc_rcv_wnd;
220 		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
221 	};
222 
223 	refcount_t		skc_refcnt;
224 	/* private: */
225 	int                     skc_dontcopy_end[0];
226 	union {
227 		u32		skc_rxhash;
228 		u32		skc_window_clamp;
229 		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
230 	};
231 	/* public: */
232 };
233 
234 struct bpf_sk_storage;
235 
236 /**
237   *	struct sock - network layer representation of sockets
238   *	@__sk_common: shared layout with inet_timewait_sock
239   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
240   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
241   *	@sk_lock:	synchronizer
242   *	@sk_kern_sock: True if sock is using kernel lock classes
243   *	@sk_rcvbuf: size of receive buffer in bytes
244   *	@sk_wq: sock wait queue and async head
245   *	@sk_rx_dst: receive input route used by early demux
246   *	@sk_dst_cache: destination cache
247   *	@sk_dst_pending_confirm: need to confirm neighbour
248   *	@sk_policy: flow policy
249   *	@sk_receive_queue: incoming packets
250   *	@sk_wmem_alloc: transmit queue bytes committed
251   *	@sk_tsq_flags: TCP Small Queues flags
252   *	@sk_write_queue: Packet sending queue
253   *	@sk_omem_alloc: "o" is "option" or "other"
254   *	@sk_wmem_queued: persistent queue size
255   *	@sk_forward_alloc: space allocated forward
256   *	@sk_napi_id: id of the last napi context to receive data for sk
257   *	@sk_ll_usec: usecs to busypoll when there is no data
258   *	@sk_allocation: allocation mode
259   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
260   *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
261   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
262   *	@sk_sndbuf: size of send buffer in bytes
263   *	@__sk_flags_offset: empty field used to determine location of bitfield
264   *	@sk_padding: unused element for alignment
265   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
266   *	@sk_no_check_rx: allow zero checksum in RX packets
267   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
268   *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
269   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
270   *	@sk_gso_max_size: Maximum GSO segment size to build
271   *	@sk_gso_max_segs: Maximum number of GSO segments
272   *	@sk_pacing_shift: scaling factor for TCP Small Queues
273   *	@sk_lingertime: %SO_LINGER l_linger setting
274   *	@sk_backlog: always used with the per-socket spinlock held
275   *	@sk_callback_lock: used with the callbacks in the end of this struct
276   *	@sk_error_queue: rarely used
277   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
278   *			  IPV6_ADDRFORM for instance)
279   *	@sk_err: last error
280   *	@sk_err_soft: errors that don't cause failure but are the cause of a
281   *		      persistent failure not just 'timed out'
282   *	@sk_drops: raw/udp drops counter
283   *	@sk_ack_backlog: current listen backlog
284   *	@sk_max_ack_backlog: listen backlog set in listen()
285   *	@sk_uid: user id of owner
286   *	@sk_priority: %SO_PRIORITY setting
287   *	@sk_type: socket type (%SOCK_STREAM, etc)
288   *	@sk_protocol: which protocol this socket belongs in this network family
289   *	@sk_peer_pid: &struct pid for this socket's peer
290   *	@sk_peer_cred: %SO_PEERCRED setting
291   *	@sk_rcvlowat: %SO_RCVLOWAT setting
292   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
293   *	@sk_sndtimeo: %SO_SNDTIMEO setting
294   *	@sk_txhash: computed flow hash for use on transmit
295   *	@sk_filter: socket filtering instructions
296   *	@sk_timer: sock cleanup timer
297   *	@sk_stamp: time stamp of last packet received
298   *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
299   *	@sk_tsflags: SO_TIMESTAMPING socket options
300   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
301   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
302   *	@sk_socket: Identd and reporting IO signals
303   *	@sk_user_data: RPC layer private data
304   *	@sk_frag: cached page frag
305   *	@sk_peek_off: current peek_offset value
306   *	@sk_send_head: front of stuff to transmit
307   *	@sk_security: used by security modules
308   *	@sk_mark: generic packet mark
309   *	@sk_cgrp_data: cgroup data for this cgroup
310   *	@sk_memcg: this socket's memory cgroup association
311   *	@sk_write_pending: a write to stream socket waits to start
312   *	@sk_state_change: callback to indicate change in the state of the sock
313   *	@sk_data_ready: callback to indicate there is data to be processed
314   *	@sk_write_space: callback to indicate there is bf sending space available
315   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
316   *	@sk_backlog_rcv: callback to process the backlog
317   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
318   *	@sk_reuseport_cb: reuseport group container
319   *	@sk_rcu: used during RCU grace period
320   *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
321   *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
322   *	@sk_txtime_unused: unused txtime flags
323   */
324 struct sock {
325 	/*
326 	 * Now struct inet_timewait_sock also uses sock_common, so please just
327 	 * don't add nothing before this first member (__sk_common) --acme
328 	 */
329 	struct sock_common	__sk_common;
330 #define sk_node			__sk_common.skc_node
331 #define sk_nulls_node		__sk_common.skc_nulls_node
332 #define sk_refcnt		__sk_common.skc_refcnt
333 #define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
334 #ifdef CONFIG_XPS
335 #define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
336 #endif
337 
338 #define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
339 #define sk_dontcopy_end		__sk_common.skc_dontcopy_end
340 #define sk_hash			__sk_common.skc_hash
341 #define sk_portpair		__sk_common.skc_portpair
342 #define sk_num			__sk_common.skc_num
343 #define sk_dport		__sk_common.skc_dport
344 #define sk_addrpair		__sk_common.skc_addrpair
345 #define sk_daddr		__sk_common.skc_daddr
346 #define sk_rcv_saddr		__sk_common.skc_rcv_saddr
347 #define sk_family		__sk_common.skc_family
348 #define sk_state		__sk_common.skc_state
349 #define sk_reuse		__sk_common.skc_reuse
350 #define sk_reuseport		__sk_common.skc_reuseport
351 #define sk_ipv6only		__sk_common.skc_ipv6only
352 #define sk_net_refcnt		__sk_common.skc_net_refcnt
353 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
354 #define sk_bind_node		__sk_common.skc_bind_node
355 #define sk_prot			__sk_common.skc_prot
356 #define sk_net			__sk_common.skc_net
357 #define sk_v6_daddr		__sk_common.skc_v6_daddr
358 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
359 #define sk_cookie		__sk_common.skc_cookie
360 #define sk_incoming_cpu		__sk_common.skc_incoming_cpu
361 #define sk_flags		__sk_common.skc_flags
362 #define sk_rxhash		__sk_common.skc_rxhash
363 
364 	socket_lock_t		sk_lock;
365 	atomic_t		sk_drops;
366 	int			sk_rcvlowat;
367 	struct sk_buff_head	sk_error_queue;
368 	struct sk_buff		*sk_rx_skb_cache;
369 	struct sk_buff_head	sk_receive_queue;
370 	/*
371 	 * The backlog queue is special, it is always used with
372 	 * the per-socket spinlock held and requires low latency
373 	 * access. Therefore we special case it's implementation.
374 	 * Note : rmem_alloc is in this structure to fill a hole
375 	 * on 64bit arches, not because its logically part of
376 	 * backlog.
377 	 */
378 	struct {
379 		atomic_t	rmem_alloc;
380 		int		len;
381 		struct sk_buff	*head;
382 		struct sk_buff	*tail;
383 	} sk_backlog;
384 #define sk_rmem_alloc sk_backlog.rmem_alloc
385 
386 	int			sk_forward_alloc;
387 #ifdef CONFIG_NET_RX_BUSY_POLL
388 	unsigned int		sk_ll_usec;
389 	/* ===== mostly read cache line ===== */
390 	unsigned int		sk_napi_id;
391 #endif
392 	int			sk_rcvbuf;
393 
394 	struct sk_filter __rcu	*sk_filter;
395 	union {
396 		struct socket_wq __rcu	*sk_wq;
397 		struct socket_wq	*sk_wq_raw;
398 	};
399 #ifdef CONFIG_XFRM
400 	struct xfrm_policy __rcu *sk_policy[2];
401 #endif
402 	struct dst_entry	*sk_rx_dst;
403 	struct dst_entry __rcu	*sk_dst_cache;
404 	atomic_t		sk_omem_alloc;
405 	int			sk_sndbuf;
406 
407 	/* ===== cache line for TX ===== */
408 	int			sk_wmem_queued;
409 	refcount_t		sk_wmem_alloc;
410 	unsigned long		sk_tsq_flags;
411 	union {
412 		struct sk_buff	*sk_send_head;
413 		struct rb_root	tcp_rtx_queue;
414 	};
415 	struct sk_buff		*sk_tx_skb_cache;
416 	struct sk_buff_head	sk_write_queue;
417 	__s32			sk_peek_off;
418 	int			sk_write_pending;
419 	__u32			sk_dst_pending_confirm;
420 	u32			sk_pacing_status; /* see enum sk_pacing */
421 	long			sk_sndtimeo;
422 	struct timer_list	sk_timer;
423 	__u32			sk_priority;
424 	__u32			sk_mark;
425 	unsigned long		sk_pacing_rate; /* bytes per second */
426 	unsigned long		sk_max_pacing_rate;
427 	struct page_frag	sk_frag;
428 	netdev_features_t	sk_route_caps;
429 	netdev_features_t	sk_route_nocaps;
430 	netdev_features_t	sk_route_forced_caps;
431 	int			sk_gso_type;
432 	unsigned int		sk_gso_max_size;
433 	gfp_t			sk_allocation;
434 	__u32			sk_txhash;
435 
436 	/*
437 	 * Because of non atomicity rules, all
438 	 * changes are protected by socket lock.
439 	 */
440 	unsigned int		__sk_flags_offset[0];
441 #ifdef __BIG_ENDIAN_BITFIELD
442 #define SK_FL_PROTO_SHIFT  16
443 #define SK_FL_PROTO_MASK   0x00ff0000
444 
445 #define SK_FL_TYPE_SHIFT   0
446 #define SK_FL_TYPE_MASK    0x0000ffff
447 #else
448 #define SK_FL_PROTO_SHIFT  8
449 #define SK_FL_PROTO_MASK   0x0000ff00
450 
451 #define SK_FL_TYPE_SHIFT   16
452 #define SK_FL_TYPE_MASK    0xffff0000
453 #endif
454 
455 	unsigned int		sk_padding : 1,
456 				sk_kern_sock : 1,
457 				sk_no_check_tx : 1,
458 				sk_no_check_rx : 1,
459 				sk_userlocks : 4,
460 				sk_protocol  : 8,
461 				sk_type      : 16;
462 #define SK_PROTOCOL_MAX U8_MAX
463 	u16			sk_gso_max_segs;
464 	u8			sk_pacing_shift;
465 	unsigned long	        sk_lingertime;
466 	struct proto		*sk_prot_creator;
467 	rwlock_t		sk_callback_lock;
468 	int			sk_err,
469 				sk_err_soft;
470 	u32			sk_ack_backlog;
471 	u32			sk_max_ack_backlog;
472 	kuid_t			sk_uid;
473 	struct pid		*sk_peer_pid;
474 	const struct cred	*sk_peer_cred;
475 	long			sk_rcvtimeo;
476 	ktime_t			sk_stamp;
477 #if BITS_PER_LONG==32
478 	seqlock_t		sk_stamp_seq;
479 #endif
480 	u16			sk_tsflags;
481 	u8			sk_shutdown;
482 	u32			sk_tskey;
483 	atomic_t		sk_zckey;
484 
485 	u8			sk_clockid;
486 	u8			sk_txtime_deadline_mode : 1,
487 				sk_txtime_report_errors : 1,
488 				sk_txtime_unused : 6;
489 
490 	struct socket		*sk_socket;
491 	void			*sk_user_data;
492 #ifdef CONFIG_SECURITY
493 	void			*sk_security;
494 #endif
495 	struct sock_cgroup_data	sk_cgrp_data;
496 	struct mem_cgroup	*sk_memcg;
497 	void			(*sk_state_change)(struct sock *sk);
498 	void			(*sk_data_ready)(struct sock *sk);
499 	void			(*sk_write_space)(struct sock *sk);
500 	void			(*sk_error_report)(struct sock *sk);
501 	int			(*sk_backlog_rcv)(struct sock *sk,
502 						  struct sk_buff *skb);
503 #ifdef CONFIG_SOCK_VALIDATE_XMIT
504 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
505 							struct net_device *dev,
506 							struct sk_buff *skb);
507 #endif
508 	void                    (*sk_destruct)(struct sock *sk);
509 	struct sock_reuseport __rcu	*sk_reuseport_cb;
510 #ifdef CONFIG_BPF_SYSCALL
511 	struct bpf_sk_storage __rcu	*sk_bpf_storage;
512 #endif
513 	struct rcu_head		sk_rcu;
514 };
515 
516 enum sk_pacing {
517 	SK_PACING_NONE		= 0,
518 	SK_PACING_NEEDED	= 1,
519 	SK_PACING_FQ		= 2,
520 };
521 
522 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
523 
524 #define rcu_dereference_sk_user_data(sk)	rcu_dereference(__sk_user_data((sk)))
525 #define rcu_assign_sk_user_data(sk, ptr)	rcu_assign_pointer(__sk_user_data((sk)), ptr)
526 
527 /*
528  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
529  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
530  * on a socket means that the socket will reuse everybody else's port
531  * without looking at the other's sk_reuse value.
532  */
533 
534 #define SK_NO_REUSE	0
535 #define SK_CAN_REUSE	1
536 #define SK_FORCE_REUSE	2
537 
538 int sk_set_peek_off(struct sock *sk, int val);
539 
540 static inline int sk_peek_offset(struct sock *sk, int flags)
541 {
542 	if (unlikely(flags & MSG_PEEK)) {
543 		return READ_ONCE(sk->sk_peek_off);
544 	}
545 
546 	return 0;
547 }
548 
549 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
550 {
551 	s32 off = READ_ONCE(sk->sk_peek_off);
552 
553 	if (unlikely(off >= 0)) {
554 		off = max_t(s32, off - val, 0);
555 		WRITE_ONCE(sk->sk_peek_off, off);
556 	}
557 }
558 
559 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
560 {
561 	sk_peek_offset_bwd(sk, -val);
562 }
563 
564 /*
565  * Hashed lists helper routines
566  */
567 static inline struct sock *sk_entry(const struct hlist_node *node)
568 {
569 	return hlist_entry(node, struct sock, sk_node);
570 }
571 
572 static inline struct sock *__sk_head(const struct hlist_head *head)
573 {
574 	return hlist_entry(head->first, struct sock, sk_node);
575 }
576 
577 static inline struct sock *sk_head(const struct hlist_head *head)
578 {
579 	return hlist_empty(head) ? NULL : __sk_head(head);
580 }
581 
582 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
583 {
584 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
585 }
586 
587 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
588 {
589 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
590 }
591 
592 static inline struct sock *sk_next(const struct sock *sk)
593 {
594 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
595 }
596 
597 static inline struct sock *sk_nulls_next(const struct sock *sk)
598 {
599 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
600 		hlist_nulls_entry(sk->sk_nulls_node.next,
601 				  struct sock, sk_nulls_node) :
602 		NULL;
603 }
604 
605 static inline bool sk_unhashed(const struct sock *sk)
606 {
607 	return hlist_unhashed(&sk->sk_node);
608 }
609 
610 static inline bool sk_hashed(const struct sock *sk)
611 {
612 	return !sk_unhashed(sk);
613 }
614 
615 static inline void sk_node_init(struct hlist_node *node)
616 {
617 	node->pprev = NULL;
618 }
619 
620 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
621 {
622 	node->pprev = NULL;
623 }
624 
625 static inline void __sk_del_node(struct sock *sk)
626 {
627 	__hlist_del(&sk->sk_node);
628 }
629 
630 /* NB: equivalent to hlist_del_init_rcu */
631 static inline bool __sk_del_node_init(struct sock *sk)
632 {
633 	if (sk_hashed(sk)) {
634 		__sk_del_node(sk);
635 		sk_node_init(&sk->sk_node);
636 		return true;
637 	}
638 	return false;
639 }
640 
641 /* Grab socket reference count. This operation is valid only
642    when sk is ALREADY grabbed f.e. it is found in hash table
643    or a list and the lookup is made under lock preventing hash table
644    modifications.
645  */
646 
647 static __always_inline void sock_hold(struct sock *sk)
648 {
649 	refcount_inc(&sk->sk_refcnt);
650 }
651 
652 /* Ungrab socket in the context, which assumes that socket refcnt
653    cannot hit zero, f.e. it is true in context of any socketcall.
654  */
655 static __always_inline void __sock_put(struct sock *sk)
656 {
657 	refcount_dec(&sk->sk_refcnt);
658 }
659 
660 static inline bool sk_del_node_init(struct sock *sk)
661 {
662 	bool rc = __sk_del_node_init(sk);
663 
664 	if (rc) {
665 		/* paranoid for a while -acme */
666 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
667 		__sock_put(sk);
668 	}
669 	return rc;
670 }
671 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
672 
673 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
674 {
675 	if (sk_hashed(sk)) {
676 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
677 		return true;
678 	}
679 	return false;
680 }
681 
682 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
683 {
684 	bool rc = __sk_nulls_del_node_init_rcu(sk);
685 
686 	if (rc) {
687 		/* paranoid for a while -acme */
688 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
689 		__sock_put(sk);
690 	}
691 	return rc;
692 }
693 
694 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
695 {
696 	hlist_add_head(&sk->sk_node, list);
697 }
698 
699 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
700 {
701 	sock_hold(sk);
702 	__sk_add_node(sk, list);
703 }
704 
705 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
706 {
707 	sock_hold(sk);
708 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
709 	    sk->sk_family == AF_INET6)
710 		hlist_add_tail_rcu(&sk->sk_node, list);
711 	else
712 		hlist_add_head_rcu(&sk->sk_node, list);
713 }
714 
715 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
716 {
717 	sock_hold(sk);
718 	hlist_add_tail_rcu(&sk->sk_node, list);
719 }
720 
721 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
722 {
723 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
724 }
725 
726 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
727 {
728 	sock_hold(sk);
729 	__sk_nulls_add_node_rcu(sk, list);
730 }
731 
732 static inline void __sk_del_bind_node(struct sock *sk)
733 {
734 	__hlist_del(&sk->sk_bind_node);
735 }
736 
737 static inline void sk_add_bind_node(struct sock *sk,
738 					struct hlist_head *list)
739 {
740 	hlist_add_head(&sk->sk_bind_node, list);
741 }
742 
743 #define sk_for_each(__sk, list) \
744 	hlist_for_each_entry(__sk, list, sk_node)
745 #define sk_for_each_rcu(__sk, list) \
746 	hlist_for_each_entry_rcu(__sk, list, sk_node)
747 #define sk_nulls_for_each(__sk, node, list) \
748 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
749 #define sk_nulls_for_each_rcu(__sk, node, list) \
750 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
751 #define sk_for_each_from(__sk) \
752 	hlist_for_each_entry_from(__sk, sk_node)
753 #define sk_nulls_for_each_from(__sk, node) \
754 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
755 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
756 #define sk_for_each_safe(__sk, tmp, list) \
757 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
758 #define sk_for_each_bound(__sk, list) \
759 	hlist_for_each_entry(__sk, list, sk_bind_node)
760 
761 /**
762  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
763  * @tpos:	the type * to use as a loop cursor.
764  * @pos:	the &struct hlist_node to use as a loop cursor.
765  * @head:	the head for your list.
766  * @offset:	offset of hlist_node within the struct.
767  *
768  */
769 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
770 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
771 	     pos != NULL &&						       \
772 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
773 	     pos = rcu_dereference(hlist_next_rcu(pos)))
774 
775 static inline struct user_namespace *sk_user_ns(struct sock *sk)
776 {
777 	/* Careful only use this in a context where these parameters
778 	 * can not change and must all be valid, such as recvmsg from
779 	 * userspace.
780 	 */
781 	return sk->sk_socket->file->f_cred->user_ns;
782 }
783 
784 /* Sock flags */
785 enum sock_flags {
786 	SOCK_DEAD,
787 	SOCK_DONE,
788 	SOCK_URGINLINE,
789 	SOCK_KEEPOPEN,
790 	SOCK_LINGER,
791 	SOCK_DESTROY,
792 	SOCK_BROADCAST,
793 	SOCK_TIMESTAMP,
794 	SOCK_ZAPPED,
795 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
796 	SOCK_DBG, /* %SO_DEBUG setting */
797 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
798 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
799 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
800 	SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
801 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
802 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
803 	SOCK_FASYNC, /* fasync() active */
804 	SOCK_RXQ_OVFL,
805 	SOCK_ZEROCOPY, /* buffers from userspace */
806 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
807 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
808 		     * Will use last 4 bytes of packet sent from
809 		     * user-space instead.
810 		     */
811 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
812 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
813 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
814 	SOCK_TXTIME,
815 	SOCK_XDP, /* XDP is attached */
816 	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
817 };
818 
819 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
820 
821 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
822 {
823 	nsk->sk_flags = osk->sk_flags;
824 }
825 
826 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
827 {
828 	__set_bit(flag, &sk->sk_flags);
829 }
830 
831 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
832 {
833 	__clear_bit(flag, &sk->sk_flags);
834 }
835 
836 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
837 {
838 	return test_bit(flag, &sk->sk_flags);
839 }
840 
841 #ifdef CONFIG_NET
842 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
843 static inline int sk_memalloc_socks(void)
844 {
845 	return static_branch_unlikely(&memalloc_socks_key);
846 }
847 #else
848 
849 static inline int sk_memalloc_socks(void)
850 {
851 	return 0;
852 }
853 
854 #endif
855 
856 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
857 {
858 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
859 }
860 
861 static inline void sk_acceptq_removed(struct sock *sk)
862 {
863 	sk->sk_ack_backlog--;
864 }
865 
866 static inline void sk_acceptq_added(struct sock *sk)
867 {
868 	sk->sk_ack_backlog++;
869 }
870 
871 static inline bool sk_acceptq_is_full(const struct sock *sk)
872 {
873 	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
874 }
875 
876 /*
877  * Compute minimal free write space needed to queue new packets.
878  */
879 static inline int sk_stream_min_wspace(const struct sock *sk)
880 {
881 	return READ_ONCE(sk->sk_wmem_queued) >> 1;
882 }
883 
884 static inline int sk_stream_wspace(const struct sock *sk)
885 {
886 	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
887 }
888 
889 static inline void sk_wmem_queued_add(struct sock *sk, int val)
890 {
891 	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
892 }
893 
894 void sk_stream_write_space(struct sock *sk);
895 
896 /* OOB backlog add */
897 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
898 {
899 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
900 	skb_dst_force(skb);
901 
902 	if (!sk->sk_backlog.tail)
903 		sk->sk_backlog.head = skb;
904 	else
905 		sk->sk_backlog.tail->next = skb;
906 
907 	sk->sk_backlog.tail = skb;
908 	skb->next = NULL;
909 }
910 
911 /*
912  * Take into account size of receive queue and backlog queue
913  * Do not take into account this skb truesize,
914  * to allow even a single big packet to come.
915  */
916 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
917 {
918 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
919 
920 	return qsize > limit;
921 }
922 
923 /* The per-socket spinlock must be held here. */
924 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
925 					      unsigned int limit)
926 {
927 	if (sk_rcvqueues_full(sk, limit))
928 		return -ENOBUFS;
929 
930 	/*
931 	 * If the skb was allocated from pfmemalloc reserves, only
932 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
933 	 * helping free memory
934 	 */
935 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
936 		return -ENOMEM;
937 
938 	__sk_add_backlog(sk, skb);
939 	sk->sk_backlog.len += skb->truesize;
940 	return 0;
941 }
942 
943 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
944 
945 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
946 {
947 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
948 		return __sk_backlog_rcv(sk, skb);
949 
950 	return sk->sk_backlog_rcv(sk, skb);
951 }
952 
953 static inline void sk_incoming_cpu_update(struct sock *sk)
954 {
955 	int cpu = raw_smp_processor_id();
956 
957 	if (unlikely(sk->sk_incoming_cpu != cpu))
958 		sk->sk_incoming_cpu = cpu;
959 }
960 
961 static inline void sock_rps_record_flow_hash(__u32 hash)
962 {
963 #ifdef CONFIG_RPS
964 	struct rps_sock_flow_table *sock_flow_table;
965 
966 	rcu_read_lock();
967 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
968 	rps_record_sock_flow(sock_flow_table, hash);
969 	rcu_read_unlock();
970 #endif
971 }
972 
973 static inline void sock_rps_record_flow(const struct sock *sk)
974 {
975 #ifdef CONFIG_RPS
976 	if (static_branch_unlikely(&rfs_needed)) {
977 		/* Reading sk->sk_rxhash might incur an expensive cache line
978 		 * miss.
979 		 *
980 		 * TCP_ESTABLISHED does cover almost all states where RFS
981 		 * might be useful, and is cheaper [1] than testing :
982 		 *	IPv4: inet_sk(sk)->inet_daddr
983 		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
984 		 * OR	an additional socket flag
985 		 * [1] : sk_state and sk_prot are in the same cache line.
986 		 */
987 		if (sk->sk_state == TCP_ESTABLISHED)
988 			sock_rps_record_flow_hash(sk->sk_rxhash);
989 	}
990 #endif
991 }
992 
993 static inline void sock_rps_save_rxhash(struct sock *sk,
994 					const struct sk_buff *skb)
995 {
996 #ifdef CONFIG_RPS
997 	if (unlikely(sk->sk_rxhash != skb->hash))
998 		sk->sk_rxhash = skb->hash;
999 #endif
1000 }
1001 
1002 static inline void sock_rps_reset_rxhash(struct sock *sk)
1003 {
1004 #ifdef CONFIG_RPS
1005 	sk->sk_rxhash = 0;
1006 #endif
1007 }
1008 
1009 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1010 	({	int __rc;						\
1011 		release_sock(__sk);					\
1012 		__rc = __condition;					\
1013 		if (!__rc) {						\
1014 			*(__timeo) = wait_woken(__wait,			\
1015 						TASK_INTERRUPTIBLE,	\
1016 						*(__timeo));		\
1017 		}							\
1018 		sched_annotate_sleep();					\
1019 		lock_sock(__sk);					\
1020 		__rc = __condition;					\
1021 		__rc;							\
1022 	})
1023 
1024 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1025 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1026 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1027 int sk_stream_error(struct sock *sk, int flags, int err);
1028 void sk_stream_kill_queues(struct sock *sk);
1029 void sk_set_memalloc(struct sock *sk);
1030 void sk_clear_memalloc(struct sock *sk);
1031 
1032 void __sk_flush_backlog(struct sock *sk);
1033 
1034 static inline bool sk_flush_backlog(struct sock *sk)
1035 {
1036 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1037 		__sk_flush_backlog(sk);
1038 		return true;
1039 	}
1040 	return false;
1041 }
1042 
1043 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1044 
1045 struct request_sock_ops;
1046 struct timewait_sock_ops;
1047 struct inet_hashinfo;
1048 struct raw_hashinfo;
1049 struct smc_hashinfo;
1050 struct module;
1051 
1052 /*
1053  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1054  * un-modified. Special care is taken when initializing object to zero.
1055  */
1056 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1057 {
1058 	if (offsetof(struct sock, sk_node.next) != 0)
1059 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1060 	memset(&sk->sk_node.pprev, 0,
1061 	       size - offsetof(struct sock, sk_node.pprev));
1062 }
1063 
1064 /* Networking protocol blocks we attach to sockets.
1065  * socket layer -> transport layer interface
1066  */
1067 struct proto {
1068 	void			(*close)(struct sock *sk,
1069 					long timeout);
1070 	int			(*pre_connect)(struct sock *sk,
1071 					struct sockaddr *uaddr,
1072 					int addr_len);
1073 	int			(*connect)(struct sock *sk,
1074 					struct sockaddr *uaddr,
1075 					int addr_len);
1076 	int			(*disconnect)(struct sock *sk, int flags);
1077 
1078 	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
1079 					  bool kern);
1080 
1081 	int			(*ioctl)(struct sock *sk, int cmd,
1082 					 unsigned long arg);
1083 	int			(*init)(struct sock *sk);
1084 	void			(*destroy)(struct sock *sk);
1085 	void			(*shutdown)(struct sock *sk, int how);
1086 	int			(*setsockopt)(struct sock *sk, int level,
1087 					int optname, char __user *optval,
1088 					unsigned int optlen);
1089 	int			(*getsockopt)(struct sock *sk, int level,
1090 					int optname, char __user *optval,
1091 					int __user *option);
1092 	void			(*keepalive)(struct sock *sk, int valbool);
1093 #ifdef CONFIG_COMPAT
1094 	int			(*compat_setsockopt)(struct sock *sk,
1095 					int level,
1096 					int optname, char __user *optval,
1097 					unsigned int optlen);
1098 	int			(*compat_getsockopt)(struct sock *sk,
1099 					int level,
1100 					int optname, char __user *optval,
1101 					int __user *option);
1102 	int			(*compat_ioctl)(struct sock *sk,
1103 					unsigned int cmd, unsigned long arg);
1104 #endif
1105 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1106 					   size_t len);
1107 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1108 					   size_t len, int noblock, int flags,
1109 					   int *addr_len);
1110 	int			(*sendpage)(struct sock *sk, struct page *page,
1111 					int offset, size_t size, int flags);
1112 	int			(*bind)(struct sock *sk,
1113 					struct sockaddr *uaddr, int addr_len);
1114 
1115 	int			(*backlog_rcv) (struct sock *sk,
1116 						struct sk_buff *skb);
1117 
1118 	void		(*release_cb)(struct sock *sk);
1119 
1120 	/* Keeping track of sk's, looking them up, and port selection methods. */
1121 	int			(*hash)(struct sock *sk);
1122 	void			(*unhash)(struct sock *sk);
1123 	void			(*rehash)(struct sock *sk);
1124 	int			(*get_port)(struct sock *sk, unsigned short snum);
1125 
1126 	/* Keeping track of sockets in use */
1127 #ifdef CONFIG_PROC_FS
1128 	unsigned int		inuse_idx;
1129 #endif
1130 
1131 	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1132 	bool			(*stream_memory_read)(const struct sock *sk);
1133 	/* Memory pressure */
1134 	void			(*enter_memory_pressure)(struct sock *sk);
1135 	void			(*leave_memory_pressure)(struct sock *sk);
1136 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1137 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1138 	/*
1139 	 * Pressure flag: try to collapse.
1140 	 * Technical note: it is used by multiple contexts non atomically.
1141 	 * All the __sk_mem_schedule() is of this nature: accounting
1142 	 * is strict, actions are advisory and have some latency.
1143 	 */
1144 	unsigned long		*memory_pressure;
1145 	long			*sysctl_mem;
1146 
1147 	int			*sysctl_wmem;
1148 	int			*sysctl_rmem;
1149 	u32			sysctl_wmem_offset;
1150 	u32			sysctl_rmem_offset;
1151 
1152 	int			max_header;
1153 	bool			no_autobind;
1154 
1155 	struct kmem_cache	*slab;
1156 	unsigned int		obj_size;
1157 	slab_flags_t		slab_flags;
1158 	unsigned int		useroffset;	/* Usercopy region offset */
1159 	unsigned int		usersize;	/* Usercopy region size */
1160 
1161 	struct percpu_counter	*orphan_count;
1162 
1163 	struct request_sock_ops	*rsk_prot;
1164 	struct timewait_sock_ops *twsk_prot;
1165 
1166 	union {
1167 		struct inet_hashinfo	*hashinfo;
1168 		struct udp_table	*udp_table;
1169 		struct raw_hashinfo	*raw_hash;
1170 		struct smc_hashinfo	*smc_hash;
1171 	} h;
1172 
1173 	struct module		*owner;
1174 
1175 	char			name[32];
1176 
1177 	struct list_head	node;
1178 #ifdef SOCK_REFCNT_DEBUG
1179 	atomic_t		socks;
1180 #endif
1181 	int			(*diag_destroy)(struct sock *sk, int err);
1182 } __randomize_layout;
1183 
1184 int proto_register(struct proto *prot, int alloc_slab);
1185 void proto_unregister(struct proto *prot);
1186 int sock_load_diag_module(int family, int protocol);
1187 
1188 #ifdef SOCK_REFCNT_DEBUG
1189 static inline void sk_refcnt_debug_inc(struct sock *sk)
1190 {
1191 	atomic_inc(&sk->sk_prot->socks);
1192 }
1193 
1194 static inline void sk_refcnt_debug_dec(struct sock *sk)
1195 {
1196 	atomic_dec(&sk->sk_prot->socks);
1197 	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1198 	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1199 }
1200 
1201 static inline void sk_refcnt_debug_release(const struct sock *sk)
1202 {
1203 	if (refcount_read(&sk->sk_refcnt) != 1)
1204 		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1205 		       sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1206 }
1207 #else /* SOCK_REFCNT_DEBUG */
1208 #define sk_refcnt_debug_inc(sk) do { } while (0)
1209 #define sk_refcnt_debug_dec(sk) do { } while (0)
1210 #define sk_refcnt_debug_release(sk) do { } while (0)
1211 #endif /* SOCK_REFCNT_DEBUG */
1212 
1213 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1214 {
1215 	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1216 		return false;
1217 
1218 	return sk->sk_prot->stream_memory_free ?
1219 		sk->sk_prot->stream_memory_free(sk, wake) : true;
1220 }
1221 
1222 static inline bool sk_stream_memory_free(const struct sock *sk)
1223 {
1224 	return __sk_stream_memory_free(sk, 0);
1225 }
1226 
1227 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1228 {
1229 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1230 	       __sk_stream_memory_free(sk, wake);
1231 }
1232 
1233 static inline bool sk_stream_is_writeable(const struct sock *sk)
1234 {
1235 	return __sk_stream_is_writeable(sk, 0);
1236 }
1237 
1238 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1239 					    struct cgroup *ancestor)
1240 {
1241 #ifdef CONFIG_SOCK_CGROUP_DATA
1242 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1243 				    ancestor);
1244 #else
1245 	return -ENOTSUPP;
1246 #endif
1247 }
1248 
1249 static inline bool sk_has_memory_pressure(const struct sock *sk)
1250 {
1251 	return sk->sk_prot->memory_pressure != NULL;
1252 }
1253 
1254 static inline bool sk_under_memory_pressure(const struct sock *sk)
1255 {
1256 	if (!sk->sk_prot->memory_pressure)
1257 		return false;
1258 
1259 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1260 	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
1261 		return true;
1262 
1263 	return !!*sk->sk_prot->memory_pressure;
1264 }
1265 
1266 static inline long
1267 sk_memory_allocated(const struct sock *sk)
1268 {
1269 	return atomic_long_read(sk->sk_prot->memory_allocated);
1270 }
1271 
1272 static inline long
1273 sk_memory_allocated_add(struct sock *sk, int amt)
1274 {
1275 	return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1276 }
1277 
1278 static inline void
1279 sk_memory_allocated_sub(struct sock *sk, int amt)
1280 {
1281 	atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1282 }
1283 
1284 static inline void sk_sockets_allocated_dec(struct sock *sk)
1285 {
1286 	percpu_counter_dec(sk->sk_prot->sockets_allocated);
1287 }
1288 
1289 static inline void sk_sockets_allocated_inc(struct sock *sk)
1290 {
1291 	percpu_counter_inc(sk->sk_prot->sockets_allocated);
1292 }
1293 
1294 static inline u64
1295 sk_sockets_allocated_read_positive(struct sock *sk)
1296 {
1297 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1298 }
1299 
1300 static inline int
1301 proto_sockets_allocated_sum_positive(struct proto *prot)
1302 {
1303 	return percpu_counter_sum_positive(prot->sockets_allocated);
1304 }
1305 
1306 static inline long
1307 proto_memory_allocated(struct proto *prot)
1308 {
1309 	return atomic_long_read(prot->memory_allocated);
1310 }
1311 
1312 static inline bool
1313 proto_memory_pressure(struct proto *prot)
1314 {
1315 	if (!prot->memory_pressure)
1316 		return false;
1317 	return !!*prot->memory_pressure;
1318 }
1319 
1320 
1321 #ifdef CONFIG_PROC_FS
1322 /* Called with local bh disabled */
1323 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1324 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1325 int sock_inuse_get(struct net *net);
1326 #else
1327 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1328 		int inc)
1329 {
1330 }
1331 #endif
1332 
1333 
1334 /* With per-bucket locks this operation is not-atomic, so that
1335  * this version is not worse.
1336  */
1337 static inline int __sk_prot_rehash(struct sock *sk)
1338 {
1339 	sk->sk_prot->unhash(sk);
1340 	return sk->sk_prot->hash(sk);
1341 }
1342 
1343 /* About 10 seconds */
1344 #define SOCK_DESTROY_TIME (10*HZ)
1345 
1346 /* Sockets 0-1023 can't be bound to unless you are superuser */
1347 #define PROT_SOCK	1024
1348 
1349 #define SHUTDOWN_MASK	3
1350 #define RCV_SHUTDOWN	1
1351 #define SEND_SHUTDOWN	2
1352 
1353 #define SOCK_SNDBUF_LOCK	1
1354 #define SOCK_RCVBUF_LOCK	2
1355 #define SOCK_BINDADDR_LOCK	4
1356 #define SOCK_BINDPORT_LOCK	8
1357 
1358 struct socket_alloc {
1359 	struct socket socket;
1360 	struct inode vfs_inode;
1361 };
1362 
1363 static inline struct socket *SOCKET_I(struct inode *inode)
1364 {
1365 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1366 }
1367 
1368 static inline struct inode *SOCK_INODE(struct socket *socket)
1369 {
1370 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1371 }
1372 
1373 /*
1374  * Functions for memory accounting
1375  */
1376 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1377 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1378 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1379 void __sk_mem_reclaim(struct sock *sk, int amount);
1380 
1381 /* We used to have PAGE_SIZE here, but systems with 64KB pages
1382  * do not necessarily have 16x time more memory than 4KB ones.
1383  */
1384 #define SK_MEM_QUANTUM 4096
1385 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1386 #define SK_MEM_SEND	0
1387 #define SK_MEM_RECV	1
1388 
1389 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1390 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1391 {
1392 	long val = sk->sk_prot->sysctl_mem[index];
1393 
1394 #if PAGE_SIZE > SK_MEM_QUANTUM
1395 	val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1396 #elif PAGE_SIZE < SK_MEM_QUANTUM
1397 	val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1398 #endif
1399 	return val;
1400 }
1401 
1402 static inline int sk_mem_pages(int amt)
1403 {
1404 	return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1405 }
1406 
1407 static inline bool sk_has_account(struct sock *sk)
1408 {
1409 	/* return true if protocol supports memory accounting */
1410 	return !!sk->sk_prot->memory_allocated;
1411 }
1412 
1413 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1414 {
1415 	if (!sk_has_account(sk))
1416 		return true;
1417 	return size <= sk->sk_forward_alloc ||
1418 		__sk_mem_schedule(sk, size, SK_MEM_SEND);
1419 }
1420 
1421 static inline bool
1422 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1423 {
1424 	if (!sk_has_account(sk))
1425 		return true;
1426 	return size<= sk->sk_forward_alloc ||
1427 		__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1428 		skb_pfmemalloc(skb);
1429 }
1430 
1431 static inline void sk_mem_reclaim(struct sock *sk)
1432 {
1433 	if (!sk_has_account(sk))
1434 		return;
1435 	if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1436 		__sk_mem_reclaim(sk, sk->sk_forward_alloc);
1437 }
1438 
1439 static inline void sk_mem_reclaim_partial(struct sock *sk)
1440 {
1441 	if (!sk_has_account(sk))
1442 		return;
1443 	if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1444 		__sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1445 }
1446 
1447 static inline void sk_mem_charge(struct sock *sk, int size)
1448 {
1449 	if (!sk_has_account(sk))
1450 		return;
1451 	sk->sk_forward_alloc -= size;
1452 }
1453 
1454 static inline void sk_mem_uncharge(struct sock *sk, int size)
1455 {
1456 	if (!sk_has_account(sk))
1457 		return;
1458 	sk->sk_forward_alloc += size;
1459 
1460 	/* Avoid a possible overflow.
1461 	 * TCP send queues can make this happen, if sk_mem_reclaim()
1462 	 * is not called and more than 2 GBytes are released at once.
1463 	 *
1464 	 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1465 	 * no need to hold that much forward allocation anyway.
1466 	 */
1467 	if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1468 		__sk_mem_reclaim(sk, 1 << 20);
1469 }
1470 
1471 DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
1472 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1473 {
1474 	sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1475 	sk_wmem_queued_add(sk, -skb->truesize);
1476 	sk_mem_uncharge(sk, skb->truesize);
1477 	if (static_branch_unlikely(&tcp_tx_skb_cache_key) &&
1478 	    !sk->sk_tx_skb_cache && !skb_cloned(skb)) {
1479 		skb_zcopy_clear(skb, true);
1480 		sk->sk_tx_skb_cache = skb;
1481 		return;
1482 	}
1483 	__kfree_skb(skb);
1484 }
1485 
1486 static inline void sock_release_ownership(struct sock *sk)
1487 {
1488 	if (sk->sk_lock.owned) {
1489 		sk->sk_lock.owned = 0;
1490 
1491 		/* The sk_lock has mutex_unlock() semantics: */
1492 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1493 	}
1494 }
1495 
1496 /*
1497  * Macro so as to not evaluate some arguments when
1498  * lockdep is not enabled.
1499  *
1500  * Mark both the sk_lock and the sk_lock.slock as a
1501  * per-address-family lock class.
1502  */
1503 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1504 do {									\
1505 	sk->sk_lock.owned = 0;						\
1506 	init_waitqueue_head(&sk->sk_lock.wq);				\
1507 	spin_lock_init(&(sk)->sk_lock.slock);				\
1508 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1509 			sizeof((sk)->sk_lock));				\
1510 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1511 				(skey), (sname));				\
1512 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1513 } while (0)
1514 
1515 #ifdef CONFIG_LOCKDEP
1516 static inline bool lockdep_sock_is_held(const struct sock *sk)
1517 {
1518 	return lockdep_is_held(&sk->sk_lock) ||
1519 	       lockdep_is_held(&sk->sk_lock.slock);
1520 }
1521 #endif
1522 
1523 void lock_sock_nested(struct sock *sk, int subclass);
1524 
1525 static inline void lock_sock(struct sock *sk)
1526 {
1527 	lock_sock_nested(sk, 0);
1528 }
1529 
1530 void __release_sock(struct sock *sk);
1531 void release_sock(struct sock *sk);
1532 
1533 /* BH context may only use the following locking interface. */
1534 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1535 #define bh_lock_sock_nested(__sk) \
1536 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1537 				SINGLE_DEPTH_NESTING)
1538 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1539 
1540 bool lock_sock_fast(struct sock *sk);
1541 /**
1542  * unlock_sock_fast - complement of lock_sock_fast
1543  * @sk: socket
1544  * @slow: slow mode
1545  *
1546  * fast unlock socket for user context.
1547  * If slow mode is on, we call regular release_sock()
1548  */
1549 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1550 {
1551 	if (slow)
1552 		release_sock(sk);
1553 	else
1554 		spin_unlock_bh(&sk->sk_lock.slock);
1555 }
1556 
1557 /* Used by processes to "lock" a socket state, so that
1558  * interrupts and bottom half handlers won't change it
1559  * from under us. It essentially blocks any incoming
1560  * packets, so that we won't get any new data or any
1561  * packets that change the state of the socket.
1562  *
1563  * While locked, BH processing will add new packets to
1564  * the backlog queue.  This queue is processed by the
1565  * owner of the socket lock right before it is released.
1566  *
1567  * Since ~2.3.5 it is also exclusive sleep lock serializing
1568  * accesses from user process context.
1569  */
1570 
1571 static inline void sock_owned_by_me(const struct sock *sk)
1572 {
1573 #ifdef CONFIG_LOCKDEP
1574 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1575 #endif
1576 }
1577 
1578 static inline bool sock_owned_by_user(const struct sock *sk)
1579 {
1580 	sock_owned_by_me(sk);
1581 	return sk->sk_lock.owned;
1582 }
1583 
1584 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1585 {
1586 	return sk->sk_lock.owned;
1587 }
1588 
1589 /* no reclassification while locks are held */
1590 static inline bool sock_allow_reclassification(const struct sock *csk)
1591 {
1592 	struct sock *sk = (struct sock *)csk;
1593 
1594 	return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1595 }
1596 
1597 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1598 		      struct proto *prot, int kern);
1599 void sk_free(struct sock *sk);
1600 void sk_destruct(struct sock *sk);
1601 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1602 void sk_free_unlock_clone(struct sock *sk);
1603 
1604 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1605 			     gfp_t priority);
1606 void __sock_wfree(struct sk_buff *skb);
1607 void sock_wfree(struct sk_buff *skb);
1608 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1609 			     gfp_t priority);
1610 void skb_orphan_partial(struct sk_buff *skb);
1611 void sock_rfree(struct sk_buff *skb);
1612 void sock_efree(struct sk_buff *skb);
1613 #ifdef CONFIG_INET
1614 void sock_edemux(struct sk_buff *skb);
1615 #else
1616 #define sock_edemux sock_efree
1617 #endif
1618 
1619 int sock_setsockopt(struct socket *sock, int level, int op,
1620 		    char __user *optval, unsigned int optlen);
1621 
1622 int sock_getsockopt(struct socket *sock, int level, int op,
1623 		    char __user *optval, int __user *optlen);
1624 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1625 		   bool timeval, bool time32);
1626 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1627 				    int noblock, int *errcode);
1628 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1629 				     unsigned long data_len, int noblock,
1630 				     int *errcode, int max_page_order);
1631 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1632 void sock_kfree_s(struct sock *sk, void *mem, int size);
1633 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1634 void sk_send_sigurg(struct sock *sk);
1635 
1636 struct sockcm_cookie {
1637 	u64 transmit_time;
1638 	u32 mark;
1639 	u16 tsflags;
1640 };
1641 
1642 static inline void sockcm_init(struct sockcm_cookie *sockc,
1643 			       const struct sock *sk)
1644 {
1645 	*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1646 }
1647 
1648 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1649 		     struct sockcm_cookie *sockc);
1650 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1651 		   struct sockcm_cookie *sockc);
1652 
1653 /*
1654  * Functions to fill in entries in struct proto_ops when a protocol
1655  * does not implement a particular function.
1656  */
1657 int sock_no_bind(struct socket *, struct sockaddr *, int);
1658 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1659 int sock_no_socketpair(struct socket *, struct socket *);
1660 int sock_no_accept(struct socket *, struct socket *, int, bool);
1661 int sock_no_getname(struct socket *, struct sockaddr *, int);
1662 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1663 int sock_no_listen(struct socket *, int);
1664 int sock_no_shutdown(struct socket *, int);
1665 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1666 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1667 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1668 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1669 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1670 int sock_no_mmap(struct file *file, struct socket *sock,
1671 		 struct vm_area_struct *vma);
1672 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1673 			 size_t size, int flags);
1674 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1675 				int offset, size_t size, int flags);
1676 
1677 /*
1678  * Functions to fill in entries in struct proto_ops when a protocol
1679  * uses the inet style.
1680  */
1681 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1682 				  char __user *optval, int __user *optlen);
1683 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1684 			int flags);
1685 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1686 				  char __user *optval, unsigned int optlen);
1687 int compat_sock_common_getsockopt(struct socket *sock, int level,
1688 		int optname, char __user *optval, int __user *optlen);
1689 int compat_sock_common_setsockopt(struct socket *sock, int level,
1690 		int optname, char __user *optval, unsigned int optlen);
1691 
1692 void sk_common_release(struct sock *sk);
1693 
1694 /*
1695  *	Default socket callbacks and setup code
1696  */
1697 
1698 /* Initialise core socket variables */
1699 void sock_init_data(struct socket *sock, struct sock *sk);
1700 
1701 /*
1702  * Socket reference counting postulates.
1703  *
1704  * * Each user of socket SHOULD hold a reference count.
1705  * * Each access point to socket (an hash table bucket, reference from a list,
1706  *   running timer, skb in flight MUST hold a reference count.
1707  * * When reference count hits 0, it means it will never increase back.
1708  * * When reference count hits 0, it means that no references from
1709  *   outside exist to this socket and current process on current CPU
1710  *   is last user and may/should destroy this socket.
1711  * * sk_free is called from any context: process, BH, IRQ. When
1712  *   it is called, socket has no references from outside -> sk_free
1713  *   may release descendant resources allocated by the socket, but
1714  *   to the time when it is called, socket is NOT referenced by any
1715  *   hash tables, lists etc.
1716  * * Packets, delivered from outside (from network or from another process)
1717  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1718  *   when they sit in queue. Otherwise, packets will leak to hole, when
1719  *   socket is looked up by one cpu and unhasing is made by another CPU.
1720  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1721  *   (leak to backlog). Packet socket does all the processing inside
1722  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1723  *   use separate SMP lock, so that they are prone too.
1724  */
1725 
1726 /* Ungrab socket and destroy it, if it was the last reference. */
1727 static inline void sock_put(struct sock *sk)
1728 {
1729 	if (refcount_dec_and_test(&sk->sk_refcnt))
1730 		sk_free(sk);
1731 }
1732 /* Generic version of sock_put(), dealing with all sockets
1733  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1734  */
1735 void sock_gen_put(struct sock *sk);
1736 
1737 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1738 		     unsigned int trim_cap, bool refcounted);
1739 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1740 				 const int nested)
1741 {
1742 	return __sk_receive_skb(sk, skb, nested, 1, true);
1743 }
1744 
1745 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1746 {
1747 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
1748 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1749 		return;
1750 	sk->sk_tx_queue_mapping = tx_queue;
1751 }
1752 
1753 #define NO_QUEUE_MAPPING	USHRT_MAX
1754 
1755 static inline void sk_tx_queue_clear(struct sock *sk)
1756 {
1757 	sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1758 }
1759 
1760 static inline int sk_tx_queue_get(const struct sock *sk)
1761 {
1762 	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1763 		return sk->sk_tx_queue_mapping;
1764 
1765 	return -1;
1766 }
1767 
1768 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
1769 {
1770 #ifdef CONFIG_XPS
1771 	if (skb_rx_queue_recorded(skb)) {
1772 		u16 rx_queue = skb_get_rx_queue(skb);
1773 
1774 		if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1775 			return;
1776 
1777 		sk->sk_rx_queue_mapping = rx_queue;
1778 	}
1779 #endif
1780 }
1781 
1782 static inline void sk_rx_queue_clear(struct sock *sk)
1783 {
1784 #ifdef CONFIG_XPS
1785 	sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1786 #endif
1787 }
1788 
1789 #ifdef CONFIG_XPS
1790 static inline int sk_rx_queue_get(const struct sock *sk)
1791 {
1792 	if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1793 		return sk->sk_rx_queue_mapping;
1794 
1795 	return -1;
1796 }
1797 #endif
1798 
1799 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1800 {
1801 	sk_tx_queue_clear(sk);
1802 	sk->sk_socket = sock;
1803 }
1804 
1805 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1806 {
1807 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1808 	return &rcu_dereference_raw(sk->sk_wq)->wait;
1809 }
1810 /* Detach socket from process context.
1811  * Announce socket dead, detach it from wait queue and inode.
1812  * Note that parent inode held reference count on this struct sock,
1813  * we do not release it in this function, because protocol
1814  * probably wants some additional cleanups or even continuing
1815  * to work with this socket (TCP).
1816  */
1817 static inline void sock_orphan(struct sock *sk)
1818 {
1819 	write_lock_bh(&sk->sk_callback_lock);
1820 	sock_set_flag(sk, SOCK_DEAD);
1821 	sk_set_socket(sk, NULL);
1822 	sk->sk_wq  = NULL;
1823 	write_unlock_bh(&sk->sk_callback_lock);
1824 }
1825 
1826 static inline void sock_graft(struct sock *sk, struct socket *parent)
1827 {
1828 	WARN_ON(parent->sk);
1829 	write_lock_bh(&sk->sk_callback_lock);
1830 	rcu_assign_pointer(sk->sk_wq, &parent->wq);
1831 	parent->sk = sk;
1832 	sk_set_socket(sk, parent);
1833 	sk->sk_uid = SOCK_INODE(parent)->i_uid;
1834 	security_sock_graft(sk, parent);
1835 	write_unlock_bh(&sk->sk_callback_lock);
1836 }
1837 
1838 kuid_t sock_i_uid(struct sock *sk);
1839 unsigned long sock_i_ino(struct sock *sk);
1840 
1841 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1842 {
1843 	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1844 }
1845 
1846 static inline u32 net_tx_rndhash(void)
1847 {
1848 	u32 v = prandom_u32();
1849 
1850 	return v ?: 1;
1851 }
1852 
1853 static inline void sk_set_txhash(struct sock *sk)
1854 {
1855 	sk->sk_txhash = net_tx_rndhash();
1856 }
1857 
1858 static inline void sk_rethink_txhash(struct sock *sk)
1859 {
1860 	if (sk->sk_txhash)
1861 		sk_set_txhash(sk);
1862 }
1863 
1864 static inline struct dst_entry *
1865 __sk_dst_get(struct sock *sk)
1866 {
1867 	return rcu_dereference_check(sk->sk_dst_cache,
1868 				     lockdep_sock_is_held(sk));
1869 }
1870 
1871 static inline struct dst_entry *
1872 sk_dst_get(struct sock *sk)
1873 {
1874 	struct dst_entry *dst;
1875 
1876 	rcu_read_lock();
1877 	dst = rcu_dereference(sk->sk_dst_cache);
1878 	if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1879 		dst = NULL;
1880 	rcu_read_unlock();
1881 	return dst;
1882 }
1883 
1884 static inline void dst_negative_advice(struct sock *sk)
1885 {
1886 	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1887 
1888 	sk_rethink_txhash(sk);
1889 
1890 	if (dst && dst->ops->negative_advice) {
1891 		ndst = dst->ops->negative_advice(dst);
1892 
1893 		if (ndst != dst) {
1894 			rcu_assign_pointer(sk->sk_dst_cache, ndst);
1895 			sk_tx_queue_clear(sk);
1896 			sk->sk_dst_pending_confirm = 0;
1897 		}
1898 	}
1899 }
1900 
1901 static inline void
1902 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1903 {
1904 	struct dst_entry *old_dst;
1905 
1906 	sk_tx_queue_clear(sk);
1907 	sk->sk_dst_pending_confirm = 0;
1908 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
1909 					    lockdep_sock_is_held(sk));
1910 	rcu_assign_pointer(sk->sk_dst_cache, dst);
1911 	dst_release(old_dst);
1912 }
1913 
1914 static inline void
1915 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1916 {
1917 	struct dst_entry *old_dst;
1918 
1919 	sk_tx_queue_clear(sk);
1920 	sk->sk_dst_pending_confirm = 0;
1921 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1922 	dst_release(old_dst);
1923 }
1924 
1925 static inline void
1926 __sk_dst_reset(struct sock *sk)
1927 {
1928 	__sk_dst_set(sk, NULL);
1929 }
1930 
1931 static inline void
1932 sk_dst_reset(struct sock *sk)
1933 {
1934 	sk_dst_set(sk, NULL);
1935 }
1936 
1937 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1938 
1939 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1940 
1941 static inline void sk_dst_confirm(struct sock *sk)
1942 {
1943 	if (!sk->sk_dst_pending_confirm)
1944 		sk->sk_dst_pending_confirm = 1;
1945 }
1946 
1947 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
1948 {
1949 	if (skb_get_dst_pending_confirm(skb)) {
1950 		struct sock *sk = skb->sk;
1951 		unsigned long now = jiffies;
1952 
1953 		/* avoid dirtying neighbour */
1954 		if (n->confirmed != now)
1955 			n->confirmed = now;
1956 		if (sk && sk->sk_dst_pending_confirm)
1957 			sk->sk_dst_pending_confirm = 0;
1958 	}
1959 }
1960 
1961 bool sk_mc_loop(struct sock *sk);
1962 
1963 static inline bool sk_can_gso(const struct sock *sk)
1964 {
1965 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1966 }
1967 
1968 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1969 
1970 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1971 {
1972 	sk->sk_route_nocaps |= flags;
1973 	sk->sk_route_caps &= ~flags;
1974 }
1975 
1976 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1977 					   struct iov_iter *from, char *to,
1978 					   int copy, int offset)
1979 {
1980 	if (skb->ip_summed == CHECKSUM_NONE) {
1981 		__wsum csum = 0;
1982 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
1983 			return -EFAULT;
1984 		skb->csum = csum_block_add(skb->csum, csum, offset);
1985 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1986 		if (!copy_from_iter_full_nocache(to, copy, from))
1987 			return -EFAULT;
1988 	} else if (!copy_from_iter_full(to, copy, from))
1989 		return -EFAULT;
1990 
1991 	return 0;
1992 }
1993 
1994 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1995 				       struct iov_iter *from, int copy)
1996 {
1997 	int err, offset = skb->len;
1998 
1999 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2000 				       copy, offset);
2001 	if (err)
2002 		__skb_trim(skb, offset);
2003 
2004 	return err;
2005 }
2006 
2007 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2008 					   struct sk_buff *skb,
2009 					   struct page *page,
2010 					   int off, int copy)
2011 {
2012 	int err;
2013 
2014 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2015 				       copy, skb->len);
2016 	if (err)
2017 		return err;
2018 
2019 	skb->len	     += copy;
2020 	skb->data_len	     += copy;
2021 	skb->truesize	     += copy;
2022 	sk_wmem_queued_add(sk, copy);
2023 	sk_mem_charge(sk, copy);
2024 	return 0;
2025 }
2026 
2027 /**
2028  * sk_wmem_alloc_get - returns write allocations
2029  * @sk: socket
2030  *
2031  * Returns sk_wmem_alloc minus initial offset of one
2032  */
2033 static inline int sk_wmem_alloc_get(const struct sock *sk)
2034 {
2035 	return refcount_read(&sk->sk_wmem_alloc) - 1;
2036 }
2037 
2038 /**
2039  * sk_rmem_alloc_get - returns read allocations
2040  * @sk: socket
2041  *
2042  * Returns sk_rmem_alloc
2043  */
2044 static inline int sk_rmem_alloc_get(const struct sock *sk)
2045 {
2046 	return atomic_read(&sk->sk_rmem_alloc);
2047 }
2048 
2049 /**
2050  * sk_has_allocations - check if allocations are outstanding
2051  * @sk: socket
2052  *
2053  * Returns true if socket has write or read allocations
2054  */
2055 static inline bool sk_has_allocations(const struct sock *sk)
2056 {
2057 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2058 }
2059 
2060 /**
2061  * skwq_has_sleeper - check if there are any waiting processes
2062  * @wq: struct socket_wq
2063  *
2064  * Returns true if socket_wq has waiting processes
2065  *
2066  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2067  * barrier call. They were added due to the race found within the tcp code.
2068  *
2069  * Consider following tcp code paths::
2070  *
2071  *   CPU1                CPU2
2072  *   sys_select          receive packet
2073  *   ...                 ...
2074  *   __add_wait_queue    update tp->rcv_nxt
2075  *   ...                 ...
2076  *   tp->rcv_nxt check   sock_def_readable
2077  *   ...                 {
2078  *   schedule               rcu_read_lock();
2079  *                          wq = rcu_dereference(sk->sk_wq);
2080  *                          if (wq && waitqueue_active(&wq->wait))
2081  *                              wake_up_interruptible(&wq->wait)
2082  *                          ...
2083  *                       }
2084  *
2085  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2086  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2087  * could then endup calling schedule and sleep forever if there are no more
2088  * data on the socket.
2089  *
2090  */
2091 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2092 {
2093 	return wq && wq_has_sleeper(&wq->wait);
2094 }
2095 
2096 /**
2097  * sock_poll_wait - place memory barrier behind the poll_wait call.
2098  * @filp:           file
2099  * @sock:           socket to wait on
2100  * @p:              poll_table
2101  *
2102  * See the comments in the wq_has_sleeper function.
2103  */
2104 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2105 				  poll_table *p)
2106 {
2107 	if (!poll_does_not_wait(p)) {
2108 		poll_wait(filp, &sock->wq.wait, p);
2109 		/* We need to be sure we are in sync with the
2110 		 * socket flags modification.
2111 		 *
2112 		 * This memory barrier is paired in the wq_has_sleeper.
2113 		 */
2114 		smp_mb();
2115 	}
2116 }
2117 
2118 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2119 {
2120 	if (sk->sk_txhash) {
2121 		skb->l4_hash = 1;
2122 		skb->hash = sk->sk_txhash;
2123 	}
2124 }
2125 
2126 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2127 
2128 /*
2129  *	Queue a received datagram if it will fit. Stream and sequenced
2130  *	protocols can't normally use this as they need to fit buffers in
2131  *	and play with them.
2132  *
2133  *	Inlined as it's very short and called for pretty much every
2134  *	packet ever received.
2135  */
2136 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2137 {
2138 	skb_orphan(skb);
2139 	skb->sk = sk;
2140 	skb->destructor = sock_rfree;
2141 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2142 	sk_mem_charge(sk, skb->truesize);
2143 }
2144 
2145 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2146 		    unsigned long expires);
2147 
2148 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2149 
2150 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2151 			struct sk_buff *skb, unsigned int flags,
2152 			void (*destructor)(struct sock *sk,
2153 					   struct sk_buff *skb));
2154 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2155 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2156 
2157 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2158 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2159 
2160 /*
2161  *	Recover an error report and clear atomically
2162  */
2163 
2164 static inline int sock_error(struct sock *sk)
2165 {
2166 	int err;
2167 	if (likely(!sk->sk_err))
2168 		return 0;
2169 	err = xchg(&sk->sk_err, 0);
2170 	return -err;
2171 }
2172 
2173 static inline unsigned long sock_wspace(struct sock *sk)
2174 {
2175 	int amt = 0;
2176 
2177 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2178 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2179 		if (amt < 0)
2180 			amt = 0;
2181 	}
2182 	return amt;
2183 }
2184 
2185 /* Note:
2186  *  We use sk->sk_wq_raw, from contexts knowing this
2187  *  pointer is not NULL and cannot disappear/change.
2188  */
2189 static inline void sk_set_bit(int nr, struct sock *sk)
2190 {
2191 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2192 	    !sock_flag(sk, SOCK_FASYNC))
2193 		return;
2194 
2195 	set_bit(nr, &sk->sk_wq_raw->flags);
2196 }
2197 
2198 static inline void sk_clear_bit(int nr, struct sock *sk)
2199 {
2200 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2201 	    !sock_flag(sk, SOCK_FASYNC))
2202 		return;
2203 
2204 	clear_bit(nr, &sk->sk_wq_raw->flags);
2205 }
2206 
2207 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2208 {
2209 	if (sock_flag(sk, SOCK_FASYNC)) {
2210 		rcu_read_lock();
2211 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2212 		rcu_read_unlock();
2213 	}
2214 }
2215 
2216 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2217  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2218  * Note: for send buffers, TCP works better if we can build two skbs at
2219  * minimum.
2220  */
2221 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2222 
2223 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2224 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2225 
2226 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2227 {
2228 	u32 val;
2229 
2230 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2231 		return;
2232 
2233 	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2234 
2235 	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2236 }
2237 
2238 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2239 				    bool force_schedule);
2240 
2241 /**
2242  * sk_page_frag - return an appropriate page_frag
2243  * @sk: socket
2244  *
2245  * If socket allocation mode allows current thread to sleep, it means its
2246  * safe to use the per task page_frag instead of the per socket one.
2247  */
2248 static inline struct page_frag *sk_page_frag(struct sock *sk)
2249 {
2250 	if (gfpflags_allow_blocking(sk->sk_allocation))
2251 		return &current->task_frag;
2252 
2253 	return &sk->sk_frag;
2254 }
2255 
2256 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2257 
2258 /*
2259  *	Default write policy as shown to user space via poll/select/SIGIO
2260  */
2261 static inline bool sock_writeable(const struct sock *sk)
2262 {
2263 	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2264 }
2265 
2266 static inline gfp_t gfp_any(void)
2267 {
2268 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2269 }
2270 
2271 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2272 {
2273 	return noblock ? 0 : sk->sk_rcvtimeo;
2274 }
2275 
2276 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2277 {
2278 	return noblock ? 0 : sk->sk_sndtimeo;
2279 }
2280 
2281 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2282 {
2283 	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2284 
2285 	return v ?: 1;
2286 }
2287 
2288 /* Alas, with timeout socket operations are not restartable.
2289  * Compare this to poll().
2290  */
2291 static inline int sock_intr_errno(long timeo)
2292 {
2293 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2294 }
2295 
2296 struct sock_skb_cb {
2297 	u32 dropcount;
2298 };
2299 
2300 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2301  * using skb->cb[] would keep using it directly and utilize its
2302  * alignement guarantee.
2303  */
2304 #define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \
2305 			    sizeof(struct sock_skb_cb)))
2306 
2307 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2308 			    SOCK_SKB_CB_OFFSET))
2309 
2310 #define sock_skb_cb_check_size(size) \
2311 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2312 
2313 static inline void
2314 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2315 {
2316 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2317 						atomic_read(&sk->sk_drops) : 0;
2318 }
2319 
2320 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2321 {
2322 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2323 
2324 	atomic_add(segs, &sk->sk_drops);
2325 }
2326 
2327 static inline ktime_t sock_read_timestamp(struct sock *sk)
2328 {
2329 #if BITS_PER_LONG==32
2330 	unsigned int seq;
2331 	ktime_t kt;
2332 
2333 	do {
2334 		seq = read_seqbegin(&sk->sk_stamp_seq);
2335 		kt = sk->sk_stamp;
2336 	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2337 
2338 	return kt;
2339 #else
2340 	return sk->sk_stamp;
2341 #endif
2342 }
2343 
2344 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2345 {
2346 #if BITS_PER_LONG==32
2347 	write_seqlock(&sk->sk_stamp_seq);
2348 	sk->sk_stamp = kt;
2349 	write_sequnlock(&sk->sk_stamp_seq);
2350 #else
2351 	sk->sk_stamp = kt;
2352 #endif
2353 }
2354 
2355 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2356 			   struct sk_buff *skb);
2357 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2358 			     struct sk_buff *skb);
2359 
2360 static inline void
2361 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2362 {
2363 	ktime_t kt = skb->tstamp;
2364 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2365 
2366 	/*
2367 	 * generate control messages if
2368 	 * - receive time stamping in software requested
2369 	 * - software time stamp available and wanted
2370 	 * - hardware time stamps available and wanted
2371 	 */
2372 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2373 	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2374 	    (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2375 	    (hwtstamps->hwtstamp &&
2376 	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2377 		__sock_recv_timestamp(msg, sk, skb);
2378 	else
2379 		sock_write_timestamp(sk, kt);
2380 
2381 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2382 		__sock_recv_wifi_status(msg, sk, skb);
2383 }
2384 
2385 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2386 			      struct sk_buff *skb);
2387 
2388 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2389 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2390 					  struct sk_buff *skb)
2391 {
2392 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)			| \
2393 			   (1UL << SOCK_RCVTSTAMP))
2394 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2395 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2396 
2397 	if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2398 		__sock_recv_ts_and_drops(msg, sk, skb);
2399 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2400 		sock_write_timestamp(sk, skb->tstamp);
2401 	else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2402 		sock_write_timestamp(sk, 0);
2403 }
2404 
2405 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2406 
2407 /**
2408  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2409  * @sk:		socket sending this packet
2410  * @tsflags:	timestamping flags to use
2411  * @tx_flags:	completed with instructions for time stamping
2412  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2413  *
2414  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2415  */
2416 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2417 				      __u8 *tx_flags, __u32 *tskey)
2418 {
2419 	if (unlikely(tsflags)) {
2420 		__sock_tx_timestamp(tsflags, tx_flags);
2421 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2422 		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2423 			*tskey = sk->sk_tskey++;
2424 	}
2425 	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2426 		*tx_flags |= SKBTX_WIFI_STATUS;
2427 }
2428 
2429 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2430 				     __u8 *tx_flags)
2431 {
2432 	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2433 }
2434 
2435 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2436 {
2437 	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2438 			   &skb_shinfo(skb)->tskey);
2439 }
2440 
2441 /**
2442  * sk_eat_skb - Release a skb if it is no longer needed
2443  * @sk: socket to eat this skb from
2444  * @skb: socket buffer to eat
2445  *
2446  * This routine must be called with interrupts disabled or with the socket
2447  * locked so that the sk_buff queue operation is ok.
2448 */
2449 DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
2450 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2451 {
2452 	__skb_unlink(skb, &sk->sk_receive_queue);
2453 	if (static_branch_unlikely(&tcp_rx_skb_cache_key) &&
2454 	    !sk->sk_rx_skb_cache) {
2455 		sk->sk_rx_skb_cache = skb;
2456 		skb_orphan(skb);
2457 		return;
2458 	}
2459 	__kfree_skb(skb);
2460 }
2461 
2462 static inline
2463 struct net *sock_net(const struct sock *sk)
2464 {
2465 	return read_pnet(&sk->sk_net);
2466 }
2467 
2468 static inline
2469 void sock_net_set(struct sock *sk, struct net *net)
2470 {
2471 	write_pnet(&sk->sk_net, net);
2472 }
2473 
2474 static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2475 {
2476 	if (skb->sk) {
2477 		struct sock *sk = skb->sk;
2478 
2479 		skb->destructor = NULL;
2480 		skb->sk = NULL;
2481 		return sk;
2482 	}
2483 	return NULL;
2484 }
2485 
2486 /* This helper checks if a socket is a full socket,
2487  * ie _not_ a timewait or request socket.
2488  */
2489 static inline bool sk_fullsock(const struct sock *sk)
2490 {
2491 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2492 }
2493 
2494 /* Checks if this SKB belongs to an HW offloaded socket
2495  * and whether any SW fallbacks are required based on dev.
2496  * Check decrypted mark in case skb_orphan() cleared socket.
2497  */
2498 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2499 						   struct net_device *dev)
2500 {
2501 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2502 	struct sock *sk = skb->sk;
2503 
2504 	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2505 		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2506 #ifdef CONFIG_TLS_DEVICE
2507 	} else if (unlikely(skb->decrypted)) {
2508 		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2509 		kfree_skb(skb);
2510 		skb = NULL;
2511 #endif
2512 	}
2513 #endif
2514 
2515 	return skb;
2516 }
2517 
2518 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2519  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2520  */
2521 static inline bool sk_listener(const struct sock *sk)
2522 {
2523 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2524 }
2525 
2526 void sock_enable_timestamp(struct sock *sk, int flag);
2527 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2528 		       int type);
2529 
2530 bool sk_ns_capable(const struct sock *sk,
2531 		   struct user_namespace *user_ns, int cap);
2532 bool sk_capable(const struct sock *sk, int cap);
2533 bool sk_net_capable(const struct sock *sk, int cap);
2534 
2535 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2536 
2537 /* Take into consideration the size of the struct sk_buff overhead in the
2538  * determination of these values, since that is non-constant across
2539  * platforms.  This makes socket queueing behavior and performance
2540  * not depend upon such differences.
2541  */
2542 #define _SK_MEM_PACKETS		256
2543 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
2544 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2545 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2546 
2547 extern __u32 sysctl_wmem_max;
2548 extern __u32 sysctl_rmem_max;
2549 
2550 extern int sysctl_tstamp_allow_data;
2551 extern int sysctl_optmem_max;
2552 
2553 extern __u32 sysctl_wmem_default;
2554 extern __u32 sysctl_rmem_default;
2555 
2556 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2557 
2558 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2559 {
2560 	/* Does this proto have per netns sysctl_wmem ? */
2561 	if (proto->sysctl_wmem_offset)
2562 		return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2563 
2564 	return *proto->sysctl_wmem;
2565 }
2566 
2567 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2568 {
2569 	/* Does this proto have per netns sysctl_rmem ? */
2570 	if (proto->sysctl_rmem_offset)
2571 		return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2572 
2573 	return *proto->sysctl_rmem;
2574 }
2575 
2576 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2577  * Some wifi drivers need to tweak it to get more chunks.
2578  * They can use this helper from their ndo_start_xmit()
2579  */
2580 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2581 {
2582 	if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val)
2583 		return;
2584 	sk->sk_pacing_shift = val;
2585 }
2586 
2587 /* if a socket is bound to a device, check that the given device
2588  * index is either the same or that the socket is bound to an L3
2589  * master device and the given device index is also enslaved to
2590  * that L3 master
2591  */
2592 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2593 {
2594 	int mdif;
2595 
2596 	if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2597 		return true;
2598 
2599 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2600 	if (mdif && mdif == sk->sk_bound_dev_if)
2601 		return true;
2602 
2603 	return false;
2604 }
2605 
2606 #endif	/* _SOCK_H */
2607